The primary objective of this study is to investigate risk factors for coronary heart disease (CHD) and stroke in the elderly (aged 65-84). Both risk factors established in middle-aged populations and suspected risk factors will be examined. Since atherosclerosis is prevalent in the elderly, the study will focus on factors thought to induce clinically overt disease. It will do so in two ways: 1) It will assess the prediction of clinical disease from measures of preclinical disease, such as carotid atherosclerosis, left ventricular impairment, and arrhythmias or episodes of myocardial ischemia. 2) Since cardiovascular events may occur in elderly people as a result of health or life circumstances which may have changed in the months preceding the event, the study will contact participants at frequent intervals to evaluate their status with respect to concurrent disease, social support networks, stressful life situations, diet, physical activity and other risk factors. The study has three secondary objectives pertaining to the elderly populations: 1) to evaluate the factors associated with preclinical cardiovascular diseases (such as carotid atherosclerosis, left ventricular impairment and episodes of arrhythmia or myocardial ischemia); 2) to evaluate predictors of disability, institutionalization and mortality to participants who have CHD or stroke; and 3) to measure the utilization and impact of medical care services for CHD and stroke. The contractor shall serve as a Field Center for this study. The duties of the Field Centers include recruitment of an appropriate cohort, conduct interviews and clinical examinations, surveillance of the cohort, and data analysis.